Roof drain for floating roof tank



Oct. 27, 1964 c. E. BAKER ROOF DRAIN FOR FLOATING ROOF TANK 3Sheets-Sheet 1 Filed July 25, 1962 3/ on 2 9k mm mm on 3 lllli z mm mmoz=m Swoonv. 2 L 2 EE m 9 9k Fm 3 INVENTOR. C. E. BAKER BYWWW ATTORNEYSOct. 27, 1964 c. E. BAKER 3,154,214

ROOF DRAIN FOR FLOATING ROOF TANK Filed July 25, 1962 3 Sheets-Sheet 2INVENTOR. C.E. BAKER M ff A 7' TURNED S Oct. 27, 1964 c. E. BAKER ROOFDRAIN FOR FLOATING ROOF TANK 3 Sheets-Sheet 3 Filed July 25, 1962 TOPIPE FIGS INVENTOR. C.E. BAKER ATTORNEYS United States Patent 3,l54,2l4ROOF ERAEN FOR FLOATELJG ROOF T Carl E. Baker, Kansas tl'ity, Kana,assigns;- to Phillips Petroleum Company, a corporation of Delaware FiledJuly 25, 1952, Ser. No. 2,403 7 Claims. (Cl. Mil-26) This inventionrelates to floating roof storage tanks. In one aspect it relates to adrain system for disposal of water from the floating roofs of floatingroof storage tanks.

Various types of floating roof liquid storage tanks are known in theart. For the most part these tanks comprise a generally cylindricalupright wall having a floating roof which is supported by the liquid inthe tank. The peripheral edge of the roof is provided with a suitablesealing means that slides up and down the inner surface of the tank wallas the roof rises and falls due to variations in the level or" theliquid in the tank. It is, of course, apparent that the roof cannotengage the wall so closely as to prevent movement of the roof inresponse to changes in liquid level.

Obviously, rain water must not be allowed to accumulate on such roofs.Disposal of such water is a problem because of the movement of the roofsup and down as the tanks are filled and emptied.

In order to prevent leakage of water into the tank at the periphery ofthe floating roof it is general practice to position a sump near thecenter of the roof at the lowest point thereon to collect water. Thissump is, in turn, connected to a drain outlet near the bottom of thetank. Since the roof is movable, the means connecting the sump with thedrain outlet must be sufllciently flexible to allow movement of theroof. One drainage system that has been used heretofore employs ajointed metal drainage pipe assembly which is connected at one end tothe sump and at the other end to an outlet near the bottom of the tank.The joints of these metal drainage pipes frequently are swivel joints.However, such joints have been a source of trouble and often developleaks which necessitate frequent repairs. A problem is presented becauseworkmen cannot enter the tank until it has been sufliciently vented toremove toxic vapors and gases the removal of which is, of course, costlyand time consuming.

Another drainage system that has been used comprise a long, flexibleconduit attached at one end to the sump at the roof and at the other endto an external drain outlet. While this system eliminates several of thedifliculties inherent in the jointed pipe system, it has not beenentirely satisfactory from a maintenance standpoint. Occasional repairand replacement of the flexible conduit is required. The procedure thathas generally been followed in replacing this flexible conduit has beento connect one end of a line to the upper end of the conduit near thesump and to withdraw the conduit from the tank through the drain openingin the wall. The line is then attached to a new conduit which is drawninto the tank through the drain opening. This system, however, requiresa crew of workmen operating on the roof of the tank as well as a crew onthe ground. In case the flexible conduit has broken at a point withinthe tank, such a procedure cannot be followed and the tank must becompletely emptied and freed from toxic and explosive vapors.

An object of this invention is to provide a water drain system for afloating roof tank which is simple in operation and requires a minimumof maintenance. Another object of this invention is to provide such adrain system having flexible joints which, during rising and lowering ofthe roof, bend or flex only slightly. Still another object of thisinvention is to provide such a water draw system in which he flexiblejoints carry substantially no weight. Still other objects and advantagesof this invention will he realized upon reading the followingdescription which, taken with the attached drawing, forms a part of thisspecification.

in the drawing FIGURE 1 is an elevation View, partly in section, of afloating roof tank illustrating the assembly and operation of the drainsystem of this invention. FEGURES 2, 3 and 4 are isometric views ofportions of the apparatus illustrated in FIGURE 1. FIGURES 3a and 4a areside views of a portion of the apparatus of FIGURES 3 and 4,respectively. FIGURE 5 is a portion of the apparatus of FlGURE 1.

The drain system of this invention comprises, broadly, a plurality ofpipes one of which is connected with the sump in the roof of the tankand the remaining pipes lead prog essively from this first-mentionedpipe to the outlet pipe in the wall of the tank near the bottom. Eachpair of adjacent pipes is connected with one or more flexible conduitsso arranged that these flexible conduits need never to bend more than arelatively few degrees, i.e., none of these flexible conduits need everbend even as much as 45-degrees.

Referring now to the drawing, and specifically to FEGURE 1, referencenumeral 11 refers to a conventional tank, partly in section, having afloating root 12 positioned near the top of the tank. The tank isillustrated as being substantially full of liquid. A drain line assembly13 is positioned in this tank according to this invention. The waterinlet end of the drain line assembly is connected with well or sump 14at the center of the floating roof l2 and water from this sump then willflow through pipes 55, 5d, 53, 52 and thence from the tank through pipe2'7. Each of these several just-mentioned pipes are usually ordinarysteel pipes. Connecting pipes 54 and 55 and connecting pipes 52 and 27are flexible conduits or flexible conduit assemblies illustrated inFIGURE 2 and identifled by reference numeral 15. Connecting pipe 54 withpipe 53 is a flexible connection 17 and illustrated in detail in FIGURE4. Connecting pipes 53 and 52 is a flexible connection 16 andillustrated in detail in FlGURE 3.

On reference to FIGURE 2 the flexible connection 15 connects pipes 52and 27. A flexible tube 51 comprises, for example, a neoprene tubesurrounded by a woven metal protective cover. This flexible tubingassembly is provided with flanges 2d and 25 on the ends thereof forattaching to pipe flanges. Pipes 27 and 52 are provided with flangeswhich are backed up by plates 13 and channel irons 18a.

The ends of these members, that is, the plates and channel irons, arewelded to T-irons 19, 21, as illustrated. The T-irons 2 3. areillustrated as being attached to the structural members adjacent pipe 52while T-irons 19 are illustrated as being attached to the plate andchannel irons attached to pipe 27. A bearing plate 29 is attached to theend of each T-iron 19 while a bearing plate 22 is attached to each endof the T-irons 21 as illustrated. Each of these bearing plates has ahole through it for accommodation or" a bolt or pivot 23. Two of thesebolts or pivots 23 are required because of the presence of the flexibletubing 51 between the support side members. The bolts are held inposition by a pair of lock nuts in a conventional manner.

As illustrated in FIGURE 1, the flexible joint member 15 need not bebent or flexed through a very sharp angle. in fact, the angle isordinarily not more than a maximum of 25 to 30 degrees.

The flexible joint member 15 which connects pipes 54 and 55' is justexactly like the member just discussed relative to the connectionbetween pipes 27 and 52.. As

3 illustrated in FIGURE 1, this upper flexible joint 15 will be bent atan angle of about 45 degrees from a straight angle when the roof of thetank is at its uppermost position.

These flexible connections may be termed flexible Us and when the upperflexible L 15 is bent or flexed through an angle of about 45 degreesfrom a straight angle, the L may be conventionally termed a l35-degree Lor rather a 45-degree L. Thus, in the same manner the L 15 positioned atthe bottom of the tank will be termed a 25- or 30-degree L.

On reference to FIGURE 3, which is an isometric view illustrating theconstruction of the flexible joint 16 of FIGURE 1, reference should alsobe made to FIG- URE 3a. FIGURE 3a comprises a pipe L 31, which, in thecase of assembly 16, is a ISO-degree L, i.e., the acute angle betweenthe axes is a 30-degree angle and the outside or obtuse angle being theremainder of 180 degrees or 150 degress. To each end of the pipe L 31 isattached fluid-tight a flexible tube 33 similar to the flexible tube 51described relative to FIGURE 2. The ends of these flexible tubingsremote from the pipe L are provided with flanges having openings forattaching to pipe flanges or the like. Welded to the side center of theL 31 is a slotted bar 32. A similar slotted bar is likewise welded tothe back side of the L 31. These sloted bars are clearly illustrated inFIGURE 3. On reference to FIGURE 3, this flexible tube and L assembly isattached to the ends of pipes 52 and 53 in the same manner that the endof the flexible tube of assembly 15 was attached to its end of pipe 52.T-irons 34 are welded at one end to the plate 18 and channel iron 18a sothat the T-irons are positioned parallel to the longitudinal axis of thepipe 53 and there is similar positioning of corresponding membersparallel to the axis of pipe 52. Several bearing plates 35 are providedw'th openings through which a pivot or bolt 36 is inserted. This pivot36 also is positioned through the slots in the slotted bars 32. The endsof the pivot 36 are threaded for accommodation of either lock nuts orlock Washers and ordinary nuts for maintaining the pivot permanently inits operable position. The lower T-iron supports along the sides of theflexible tubing 33 are identified in FIGURE 3 by reference numeral 37.The bearing plates attached to the lower T-irons 37 are identified byreference numeral 38. A spacer rod 39 is welded to the mutually facingsides of the bearing plates 35 to maintain the side assemblies rigidlyspaced from one another with ample room between them for accommodationof the flexible tubes and pipe L.

As will be realized, upon increasing the angle between pipes 52 and 53,the slotted bar 32 will move from right to left in FIGURE 3 and,conversely as pipe 53 approaches pipe 52 with the angle therebetweenbecoming smaller, the slotted bar 32 will move from left to right. Asmentioned hereinabove relative to the flexible assemblies 15, thisflexible assembly 16 will provide for flexing of the flexible members 33only through relatively small angles and, at the same time, allow thepipes 52 and 53 to become separated by a relatively large angle.

The flexible assembly 17, illustrated in perspective in FIGURE 4, isconstructed along the same general lines as assembly 16. This assembly17 is provided with side T-irons 40 and slotted bearing plates 41 havingelongated slots 47. The slotted bearing plates 41 differ from thebearing plates of FIGURE 3 since the plates of FIGURE 3 contained merelya circular opening for accommodation of pivot 36. The plates 41a containonly circular openings for pivot 36. On reference to FIGURE 4a, theconstruction of the flexible joint member is illustrated. This flexiblemember comprises flexible tubes 44 similar to the corresponding tubes33, mentioned hereinbefore. L 43 is, in this case, a l60-degree L whichprovides an acute angle of 20 degrees between the axes of the endsthereof. A slotted plate 46 is constructed somewhat diflerent from thecorresponding slotted bar illustrated in FIGURE 3a. This slotted plate46 is provided with a more or less rectangular slot of considerablearea. This slotted plate is welded to one side of the L 43 while asimilar slotted plate is attached by welding to the opposite side of L43. The positioning of these two slotted plates 46 is clearly shown inFIGURE 4.

A pivot 45, threaded on both ends or it can be a bolt, is insertedthrough the openings in the several bearing plates 41, 41a, and throughthe rectangular openings in the slotted plates 46. As the ends of tubes44 open or close the angle between them, pipe 54 with its end supportT-irons 40 and bearing plates 41 can move longitudinally with respect tothe pipe by reason of slots 47 in the bearing plates 41. To accommodatethis movement and still maintain the pipe L 43 in a proper position, theutility of the rectangular openings in the slotted plates 46 becomesapparent. While the bearing plates 41 are provided with slottedopenings, the bearing plates 41a are provided merely with circularopenings. Thus, the pivot 45 will remain in a definite position in theopenings in bearing plates 41a while bearing plates 41 and pipe 54 canmove axially with respect to the pipe.

The pipe 55 is attached to the wall of well 14 by flanges or means notshown. A support Y-member 49, FIGURE 5 is supported through the roof ofthe tank by a flange or nuts attached to the upper end thereof or byother means if desired.

The Wall outlet assembly 26, through which pipe 27 extends, isillustrated in detail in FIGURE 1, this assembly, for illustrativepurposes, comprises a short section of a relatively large diameter pipe29 having a flange 55 on its outer end mating with a flange 28 throughwhich the outer portion of pipe 27 extends. Any means desired can beemployed for supporting pipe 29 in the wall of the tank. This type ofassembly illustrated is merely for exemplary purposes. A support 30 canbe merely a pair of vertical pipes attached to the bottom of the tankand across the top ends of which is a member on which pipe 27 can rest.

A chain 50 of predetermined length is attached by a pair of eyes orlinks welded to the respective pipes 53 and 54 as illustrated. Thischain limits the angle of opening of elbow assembly 17 and allows pipe54 to carry the weight of pipes 52 and 53 rather than the joint or pivotof elbow assembly 17.

In the assembly for water draining purposes as herein described, FIGURE1 illustrates this assembly when the tank roof is substantially at thetop of the tank. When the tank roof is at the bottom of the tank, theseveral pipes, that is, pipes 27, 52, 53, 54 and 55, are all parallel toone another in a fully folded condition. In order that pipe 53 will notrest against pipe 52, a support rest 48 is welded to the upper surfaceof pipe 52 at about the position illustrated in FIGURE 1. This supportor rest 48 has a small plate across its top on which pipe 53 rests.

While the several flexible tubes 33, 44, 51, have been hereinabovementioned as comprising neoprene tubing surrounded by woven metal clothfor protective purposes, these flexible tube members can also be metalhose assemblies. When they are flexible hose assemblies, they .are suchas those described in Volume II, Thomas Register, Thomas Publishing Co.,New York City, as illustrated on pages 3567 through 3573.

Such an assembly as herein disclosed has been used in a large oilrefinery tank for a considerable period of time and has been foundcompletely satisfactory without any failure whatever.

One assembly of such a. drain system has been previously constructed andinstalled outside of a tank and the upper end raised and lowered asuflicient number of times corresponding to about two years of use andthe assembly operated in a fully operable condition and no failurewhatever occurred during this simulated time test. In these cases theseveral pipes 27, 52, 53, 54 and 55, were 3-inch diameter pipes, theseveral Us and the flexible tubings 33, 44, 51 were also 3-inchdiameter. Thus, the entire assembly was a 3-inch diameter assembly whichhas been found suitable for easy and rapid removal of water from theroof of a large tank during even the heaviest of rainfalls.

That which is claimed is:

1. A flexible joint conduit assembly comprising, in operablecombination, an L conduit, the longitudinal axes of the ends of said Lconduit making a predetermined angle with each other, a separatefleiL'ble tubular member being attached fluid-tight at one end of eachto opposite ends of said L conduit, separate pipes connected fluidtightat one end of each to the respective other ends of the flexible tubularmembers, a pair of opposed rigid supports attached at one end of each tothe opposite sides of the end portions of said separate pipes adjacentthe fiexible tubular members and extending along the flexible tubularmembers and terminating beyond said L conduit, a slotted plate attachedat one end rigidly to said L conduit, an opening in each of the ends ofthe rigid supports adjacent said L conduit, and a pivot extendingthrough the slot of said slotted plate and through the openings in theends of said rigid support, said pivot being the apex of said flexiblejoint as the end of one of said pipes is moved with respect to thecorresponding end of the other of said pipes.

2. A roof drain conduit for a floating tank roof comprising, in operablecombination, a first pipe communicating at one end with a roof drainwell and the other end being positioned below said roof, a second pipe,a first flexible conduit connected at one end fluid-tight to said otherend of said first pipe and at the other end to one end of said secondpipe; 21 first flexible L comprising a second flexible conduit connectedat one end with the other end of said second pipe, a first pipe Lconnected at one end with the other end of said second flexible conduit,a third flexible conduit connected at one end with the other end of saidfirst pipe L; a third pipe connected at one end with the other end ofsaid third flexible conduit; a second flexible L comprising a fourthflexible conduit connected at one end with the other end of said thirdpipe, a second pipe L connected at one end with the other end of saidfourth flexible conduit, a fifth flexible conduit connected at one endwith the other end of said second pipe L; a fourth pipe connected at oneend with the other end of said fifth flexible conduit, a sixth flembleconduit connected at one end with the other end of said fourth pipe, afifth pipe connected at one end with the other end of said sixthflexible conduit and the other end extending to the exterior of thetank; said other end of said first pipe, said one end of said fifth pipeand both ends of each of said second, third and fourth pipes havingextension members rigidly attached thereto extending be yond said endsof said pipes, ends of said extension mernbers adjacent each otherhaving a pivot thereby forming a flexible joint in such a manner thatthe axes of said first, second, third, fourth and fifth pipes aremutually parallel when the tank roof is in its lowermost position, firstsupport means attaching the pivot at said first flexible conduit to thetank roof, second support means positioned below said one end of saidfifth pipe, a separate slotted bar rigidly attached to each pipe L, saidpivot passing through the slot of the adjacent bar, and a flexibleconnecting means of a predetermined maximum length attached to saidsecond and third pipes, this latter means being adapted to limit themaximum angle between said second and third pipes.

3. The roof drain conduit of claim 2 wherein the angle between the axesof said first pipe L at the ends thereof is less than the maximum anglebetween the axes of said second and third pipes, and the angle betweenthe axes of said second pipe L at the ends thereof is less than themaximum angle between the axes of said third and fourth pipes when theroof is at its uppermost position in its tank.

4. The assembly of claim 1 wherein the openings in the ends of the pairof supports on one of said pipes are slotted to impart additionalflexibility to said joint.

5. The assembly of claim 1 wherein said supports comprise longitudinalbars extending parallel with their respective pipes and bearing plateson each pair of plates extending toward the opposite bars, said platesoverlapping each other, and the openings for said pivot being in theoverlapping portions of said plates.

6. The assembly of claim 1 wherein the slotted plate attached to said Lconduit is provided with an elongated slot, the longitudinal axis ofwhich passes thru said pivot.

7. The assembly of claim 1 wherein the slotted plate attached to said Lconduit is provided with a relatively large substantially square slot toaccommodate maximum movement of said joint.

References Cited in the file of this patent UNlTED STATES PATENTS561,442 Schmidt June 2, 1896 1,129,308 Martin Feb. 23, 1915 1,138,281Dodge May 4, 1915 1,857,362 Day May 10, 1932 2,359,723 Hammeren Oct. 3,1944 2,717,095 Gable Sept. 6, 1955 FOREIGN PATENTS 585,775 Germany Oct.9, 1933

2. A ROOF DRAIN CONDUIT FOR A FLOATING TANK ROOF COMPRISING, IN OPERABLECOMBINATION, A FIRST PIPE COMMUNICATING AT ONE END WITH A ROOF DRAINWELL AND THE OTHER END BEING POSITIONED BELOW SAID ROOF, A SECOND PIPE,A FIRST FLEXIBLE CONDUIT CONNECTED AT ONE END FLUID-TIGHT TO SAID OTHEREND OF SAID FIRST PIPE AND AT THE OTHER END TO ONE END OF SAID SECONDPIPE; A FIRST FLEXIBLE L COMPRISING A SECOND FLEXIBLE CONDUIT CONNECTEDAT ONE END WITH THE OTHER END OF SAID SECOND PIPE, A FIRST PIPE LCONNECTED AT ONE END WITH THE OTHER END OF SAID SECOND FLEXIBLE CONDUIT,A THIRD FLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAIDFIRST PIPE L; A THIRD PIPE CONNECTED AT ONE END WITH THE OTHER END OFSAID THIRD FLEXIBLE CONDUIT; A SECOND FLEXIBLE L COMPRISING A FOURTHFLEXIBLE CONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID THIRDPIPE, A SECOND PIPE L CONNECTED AT ONE END WITH THE OTHER END OF SAIDFOURTH FLEXIBLE CONDUIT, A FIFTH FLEXIBLE CONDUIT CONNECTED AT ONE ENDWITH THE OTHER END OF SAID SECOND PIPE L; A FOURTH PIPE CONNECTED AT ONEEND WITH THE OTHER END OF SAID FIFTH FLEXIBLE CONDUIT, A SIXTH FLEXIBLECONDUIT CONNECTED AT ONE END WITH THE OTHER END OF SAID FOURTH PIPE, AFIFTH PIPE CONNECTED AT ONE END WITH THE OTHER END OF SAID SIXTHFLEXIBLE CONDUIT AND THE OTHER END EXTENDING TO THE EXTERIOR OF THETANK; SAID OTHER END OF SAID FIRST PIPE, SAID ONE END OF SAID FIFTH PIPEAND BOTH ENDS OF EACH OF SAID SECOND, THIRD AND FOURTH PIPES HAVINGEXTENSION MEMBERS RIGIDLY ATTACHED THERETO EXTENDING BEYOND SAID ENDS OFSAID PIPES, ENDS OF SAID EXTENSION MEMBERS ADJACENT EACH OTHER HAVING APIVOT THEREBY FORMING A FLEXIBLE JOINT IN SUCH A MANNER THAT THE AXES OFSAID FIRST, SECOND, THIRD, FOURTH AND FIFTH PIPES ARE MUTUALLY PARALLELWHEN THE TANK ROOF IS IN ITS LOWERMOST POSITION, FIRST SUPPORT MEANSATTACHING THE PIVOT AT SAID FIRST FLEXIBLE CONDUIT TO THE TANK ROOF,SECOND SUPPORT MEANS POSITIONED BELOW SAID ONE END OF SAID FIFTH PIPE, ASEPARATE SLOTTED BAR RIGIDLY ATTACHED TO EACH PIPE L, SAID PIVOT PASSINGTHROUGH THE SLOT OF THE ADJACENT BAR, AND A FLEXIBLE CONNECTING MEANS OFA PREDETERMINED MAXIMUM LENGTH ATTACHED TO SAID SECOND AND THIRD PIPES,THIS LATTER MEANS BEING ADAPTED TO LIMIT THE MAXIMUM ANGLE BETWEEN SAIDSECOND AND THIRD PIPES.